This research is designed to extend our understanding of the role of chromatin modifications in the function of the nucleus. We wish to extend our understanding of the nature of histone acetylation, concentrating on the rapid form of the modification as well as those histones totally unavailable for such modifications. We propose to exploit the ability of sodium butyrate to inhibit histone deacetylation. A new method for the isolation of actively transcribing genes will be tested and developed as well as a method for obtaining inactive chromatin on a reasonably large scale. Several methods for isolating replicating DNA will be utilized to ask questions on the sites of histone deposition and the nature of subsequent events.